1. Field of the Invention
The present invention relates to a photoelectric conversion device and an imaging system.
2. Description of the Related Art
A CMOS sensor including a photoelectric conversion device and transistors is known as a solid-state image sensor. A general structure of a photoelectric conversion device includes a photodiode and a peripheral circuit for reading out an optical signal from the photodiode. In a photoelectric conversion device having such a structure, it is important to suppress a dark current in order to suppress the occurrence of noise. Japanese Patent Laid-Open No. 2005-223146 discloses a technique of suppressing a dark current generated at a diffusion layer end of a reset element contacting a photodiode by covering an impurity region on the photodiode side of the reset element adjacent to the photodiode and an element isolation region with a lightly doped diffusion layer.